Hydrodynamic characteristics of a lunate shaped oscillating propulsor
journal contribution
posted on 2023-05-17, 04:25authored byLiu, P, Neil Bose
Research was conducted to study the hydrodynamic efficiency of a foil with aft-swept wing tips. A potential flow based time domain panel method was formulated to predict the performance of a lunate and rectangular foil in large amplitude, unsteady motion. Skin drag was approximated and boundary layer growth and separation were also estimated. Hydrodynamic efficiency was evaluated in terms of propulsive efficiency and thrust coefficient of the foil. Results are presented for a lunate shaped planform and for a rectangular foil. Predictions show that the lunate shaped planform has a substantially higher propulsive efficiency (13% higher) than the rectangular foil under heavy load conditions when the feathering parameter is zero, throughout a range of reduced frequencies (0.2 to 1.8). Under a medium load condition, however, the rectangular foil gave a higher propulsive efficiency at reduced frequencies less than 0.5 and the same efficiency value at a reduced frequency of 1.8. For a practical range of reduced frequencies between 0.5 and 1.0, the lunate tail gave higher propulsive efficiency. The lunate planform gave a lower thrust coefficient at a heavy load and higher thrust at a medium load condition than the rectangular planform for all reduced frequencies.
History
Publication title
Ocean Engineering
Volume
26
Issue
6
Pagination
519-530
ISSN
0029-8018
Department/School
Australian Maritime College
Publisher
Pergamon-Elsevier Science Ltd
Place of publication
The Boulevard, Langford Lane, Kidlington, Oxford, England
Rights statement
The definitive version is available at http://www.sciencedirect.com